Total Internal Reflection

Reflection of light rays at the border of two medium when the angle of incidence in an optically denser medium is greater than the critical angle

The critical angle, c

The maximum angle of incidence before the total internal reflection can occur

Value of critical angle

90 degree

Condition for total internal reflection

Light moves from denser → less dense medium

Value of critical angle for internal reflection

Incident ray angle is always bigger than critical angle

An example of total internal reflection

Fibre optic

The natural phenomena involving critical angle

Mirage

Type of reflection in prism periscope

Prism periscope use total internal reflection

Angle from normal line to the reflected ray

90 degrees is calculated from the normal line to the reflected ray

The condition that causes total internal reflection to happen

Total internal reflection happens when the light ray bend at the edge of the medium